What makes an airline experience (from the perspective of a passenger, not an employee) muslim friendly?Here are some thougths:
Food: availability and quality of halal food
Infotainment: whether they have one, do they show the direction of the qibla (is it correct!), do they show times of the upcoming prayers (are they correct). Also whether they have multiple camera views, which makes it easier to determine sunset, dawn, sunrise etc
Restrooms: whether they have enough space to make wudu comfortably and how the taps are controlled (auto sensing makes it easier). Also how easy is it to clean once you're done
Space for prayers: whether it has dedicated or available space for performing the prayers standing up
Staff: whether they have diverse (including women wearing hijab) staff at the airport and cabin crew. Also, whether they are knowledgeable about prayers etc (e.g. can recommend a spot)
Welcome others adding to and/or refining the criteria.